JP4651135B2 - Coil parts - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coil component such as a chip inductor.
[0002]
[Prior art]
A conventional coil component 50 will be described with reference to FIGS.
[0003]
First, as shown in FIG. 18, a coil portion 55 made of a wire with a covering such as urethane is wound around a magnetic core 53 formed in a drum shape and provided with terminal portions 54a and 54b protruding from both end faces of the flange portion. The coil terminals 55a and 55b are respectively wound around the terminal portions 54a and 54b.
[0004]
Next, lead frames 51a and 51b are prepared by punching out the lead frame and providing recesses 52a and 52b for supporting the terminal portions 54a and 54b in the upper center. As shown in FIG. 19, the terminals of the magnetic core 53 are prepared. The parts 54a and 54b are fitted into the recesses 52a and 52b and assembled.
[0005]
Next, after solder paste 57 is applied to the coil end tie portions of the terminal portions 54a and 54b, a soldering process (for example, the temperature condition is 400 ° C. higher than the solder melting temperature because the insulation coating must be peeled off). The soldering time is about 2 seconds), and then a cleaning process using a cleaning material such as methylene chloride is performed to remove solder and flux adhering to unnecessary portions.
[0006]
Next, the lead portions 51a and 51b are molded by the resin mold 56 while leaving the portions to be the external connection electrodes, and the lead portions 51a and 51b are cut and formed. As shown in FIG. A coil component 50 is formed by bending the exposed portion to be an external electrode into contact with the wall surface of the resin mold 56 (Japanese Utility Model Laid-Open No. 5-29107).
[0007]
Thereafter, the coil component 50 is sent to the inspection process. A series of these steps is shown in FIG.
[0008]
[Problems to be solved by the invention]
However, in the case of the conventional coil component 50 described above, if eutectic solder (liquidus temperature 183 ° C) or tin (Sn) rich solder (liquidus temperature 220 ° C) is used as the solder material, the coil The so-called copper cracks of the terminals 55a and 55b are generated, and the coil terminals 55a and 55b are thinned, resulting in a decrease in tensile strength and insufficient connection reliability. There was a problem of reaching.
[0009]
Further, in the case of the conventional coil component 50, a solder flux is also required, and there is a problem that a cleaning process is essential and the number of processes is increased.
[0010]
Furthermore, when mounting this type of coil component on a printed circuit board of an electronic device, in order to cope with environmental problems that have been increasing in recent years, there are an increasing number of cases where reflow soldering is performed with a lead-free high-temperature type solder material. For this connection, it is necessary to use a higher-temperature solder material. As such high-temperature solder (liquidus temperature of 250 ° C. or higher), since a solder material containing lead is used, there arises a problem that the working environment is deteriorated.
[0011]
The present invention has been made in view of the above circumstances, can obtain a highly reliable connection state, can reduce the manufacturing cost by reducing the number of steps, and further improves the working environment. It aims at providing the coil components which can also aim at.
[0012]
[Means for Solving the Problems]
The coil component according to the first aspect of the present invention includes a magnetic core in which a terminal portion protrudes from both side flange end faces, a coil is wound, and a coil terminal of the coil is drawn out and entangled with the terminal portion. And a lead part for external connection having a terminal receiving part provided with a concave groove in which the terminal part entangled with the coil terminal can be fitted and a protruding piece protruding outward of the concave groove, The lead portion is disposed so that a gap is formed between the end portion of the magnetic core and the end portion of the coil terminal at the terminal portion where the coil terminal is entangled. and the coil end tied portion the position along the projecting pieces of the terminal receiving portion and is fitted placed so that a, the coil terminals mounted on the terminal receiving portion is a terminal portion is tied Among them, the part placed on the protruding piece in the terminal receiving part is locally heated. And by, and it is characterized in that the terminal portion is melted connected as covered by the protrusion of the terminal receiving portion.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
[0018]
(First Embodiment) As shown in FIGS. 1 and 2, the coil component 1 according to the present embodiment has a terminal portion 2a formed in the shape of a metal rod made of iron or copper from the center portion of both side flange end faces. 2b is wound around a drum-shaped magnetic core 3 projecting outward, and a coil portion 4 using a wire with a coating such as urethane coating is wound, and the coil terminals 4a and 4b of the coil portion 4 are pulled out. The terminal portions 2a and 2b are connected to the terminal receiving portions 6a and 6b provided on the lead portions 5a and 5b for external connection formed by forming the lead frame 10 and forming the standing legs. It has a structure to let you.
As a result, as shown in FIG. 2 and FIG. 3, gaps are formed between the both side flange end surfaces of the magnetic core 3 and the lead portions 5 a and 5 b, respectively. Similarly, as clearly shown in FIGS. 2 and 3, the drawing terminal end portion of the coil terminal is located in the gap, and the coil terminal binding portion is disposed in the terminal receiving portion.
[0019]
The terminal receiving portions 6a and 6b are formed outwardly from the substantially U-shaped concave grooves 7a and 7b into which the terminal portions 2a and 2b can be fitted, and the bottom wall portions of the concave grooves 7a and 7b. Protruding elongated projecting pieces 8a and 8b are provided.
[0020]
After the terminal portions 2a and 2b are attached to the terminal receiving portions 6a and 6b, a laser light source (not shown) is used to send laser light to the terminal portions 2a and 2b and the coil terminal 4a entangled with the terminal portions 2a and 2b as shown in FIG. 4b or at least a part of the terminal receiving portions 6a and 6b of the lead to locally heat and melt the projecting pieces 8a and 8b to form the terminal portions 2a and 2b and the coil terminals 4a and 4b. Or by melting the coil terminals 4a and 4b and the terminal portions 2a and 2b and melting the coil terminals and the terminal portions into the projecting pieces of the terminal receiving portions, respectively, electrically and mechanically. Connecting.
[0021]
After that, the resin mold 11 is molded, and the lead portions 5a and 5b are cut and formed. As shown in FIG. The coil component 1 in a state of being bent so as to contact is obtained.
[0022]
The coil component 1 obtained in this way is sent to the inspection process. A series of these steps is shown in FIG.
[0023]
As the laser light locally irradiated to the terminal portion or the like by the laser light source, for example, spot light having a diameter of about 0.4 mm is used, and the irradiation target portion such as the terminal portion is irradiated for about 5 msec, for example, and the irradiation portion is 1000 °. Irradiate to a high temperature of about C and partially melt. In addition to the laser light source, local melting means such as an arc melting process, a plasma melting process, and a high frequency heating melting process can be used for the melting process. If such local heating means is used, the coil terminal, the terminal portion, the projecting piece, etc. can be partially and selectively heated, and the degree of heating can be controlled.
[0024]
The tensile strength (tensile strength along the protruding direction of the terminal portion 2a) P of the peeling test for the lead portions 5a and 5b of the terminal portions 2a and 2b melted as described above is the thickness 0 of the lead portions 5a and 5b. When the diameter of the terminal portion 2a is 0.35 mm, P = 2.5 kgf. This value is at least twice the strength (P = 0.9 kgf) in the case of connection by conventional solder.
[0025]
According to the present embodiment, the coil part 4 is wound around the magnetic core 3 provided with the terminal parts 2a, 2b protruding from the end face of the flange part, and the coil terminals 4a, 4b of the coil part 4 are respectively connected to the terminal parts 2a, 2b. The terminal portions 2a and 2b are respectively attached to terminal receiving portions 6a and 6b provided on the external connection lead portions 5a and 5b, and the terminal portions 2a and 2b are melt-processed. And the terminal portions 2a and 2b are electrically and mechanically connected to the terminal receiving portions 6a and 6b, respectively, so that the soldering process as in the conventional example is eliminated, and there is a risk of wire breakage due to copper cracking. In addition, the mechanical strength against pulling of the melted portions of the terminal portions 2a and 2b is twice or more larger than that of the conventional example, thereby providing the coil component 1 capable of obtaining a highly reliable connection state.
[0026]
Further, the cleaning process such as flux as in the conventional example is unnecessary, and the manufacturing cost can be reduced by reducing the number of processes. Furthermore, since a solder material containing lead is not used, the work environment can be improved, and further, adverse effects of lead on the surrounding environment can be prevented.
[0027]
In addition, since the terminal portions 2a and 2b are melted at a high temperature of about 1000 degrees Celsius or higher by laser light, even in the case of the coil terminals 4a and 4b using a high melting point coating material such as a polyimide coated wire, The coating of the coil terminals 4a and 4b is melted at the same time, thereby eliminating the coating peeling process of the coil terminals 4a and 4b. Furthermore, since the local heating method using laser light is adopted, at least a part of the terminal part, the coil terminal, and the terminal receiving part can be selected and heated locally, so that the influence of heat on the coil part is affected. The reliability can be improved. Furthermore, since the melting temperature is very high compared to the conventional solder connection, when soldering is performed by reflow or the like to mount this coil component on a printed circuit board, the thermal reliability of the connection part inside this coil component is high. .
[0028]
7, 8, and 9 show a modification of the terminal receiving portion 6a of the lead portion 5a in the above embodiment (the same applies to the terminal receiving portion 6b of the lead portion 5b).
[0029]
That is, as the terminal receiving portion 6a, as shown in FIG. 7, a structure including a recessed groove 7a into which the terminal portion 2a can be fitted and a protruding piece 12 protruding outward from the side wall of the recessed groove 7a. As shown in FIG. 8, a structure in which, for example, a saw-toothed uneven portion 13 is formed on the side wall of the concave groove 7a, and further, the insertion side end of the terminal portion 2a is held as shown in FIG. Thus, a structure in which a bag-like portion 15 in which a bag-like recess 14 is formed can be employed.
[0030]
By adopting the terminal receiving portions 6a having the structures shown in FIGS. 7 to 9 as described above, the terminal portions 2a are simply mounted, and each terminal receiving portion 6a is melt-processed with good workability. A good electrical and mechanical connection state can be obtained by covering the coil terminal 4a, the terminal portion 2a, and the lead portion 5a. In FIG. 7, the connection strength can be increased by covering the protrusion 12 by mainly melting the coil terminal and the terminal portion without causing the protrusion 12 to melt almost. In FIG. 8, the coil terminal and the terminal part can be mainly melted and held by the terminal receiving part. Furthermore, in FIG. 9, it can also be fusion-connected so that a terminal part may be wrapped in a bag-shaped part.
[0031]
(Second Embodiment)
10 and 11 show a second embodiment of the present invention.
[0032]
FIG. 10 shows that end members 24a and 24b in which a part of a disk made of iron or copper is cut out and terminal portions 23a and 23b project outward from the central portion are provided on both end surfaces of the magnetic core 3, respectively. It shows a structure to be attached using an adhesive.
[0033]
Further, FIG. 11 is made of iron or copper or the like, and a pair of engagement claw pieces 35a, 35b that can be engaged with a pair of engagement receiving grooves 3a, 3b provided on the flange portion of the magnetic core 3 on both upper and lower sides. Terminal members 33a and 33b are respectively constituted by end surface members 34a and 34b provided with 35a 'and 35b' and projecting terminal portions 32a and 32b outward from the central portion, respectively. And engaging (fitting) the terminal member 33b to the other end surface of the magnetic core 3 via the engagement receiving groove 3b. It is a thing.
[0034]
Even if such terminal portions 23a and 23b (FIG. 10) and terminal portions 32a and 32b (FIG. 11) are adopted, the terminal portions 23a, 23b, 32a, and 32b have the same structure as in the case of the terminal portions 2a and 2b described above. A sufficient mechanical strength against tension can be ensured, thereby providing a coil component capable of obtaining a highly reliable connection state.
[0035]
(Third embodiment)
Next, a third embodiment of the coil component of the present invention will be described with reference to FIGS.
[0036]
In this coil component, as shown in FIG. 12, a coil 44 is wound around a body portion of a magnetic core 43 having both end flanges, and a pair of semicircular metal terminal plates 42A and 42B are spaced from the end surfaces of the upper end flanges. The terminal portions 42a and 42b are formed by projecting terminal pieces in opposite directions from the terminal plates 42A and 42B, respectively, and the terminals 44a and 44b of the coil 44 are entangled with the projecting terminal portions 42a and 42b, respectively. A coil portion 40 is prepared, and one lead frame 47 is press-molded to form a pair of lead portions 45A and 45B that are disposed to face each other between the pair of connecting pieces 47b and 47b, and the tips of the lead portions 45A and 45B. A lead frame member is prepared with the upper end bent into a U-shape and the upper ends thereof as terminal receiving portions 46a and 46b, and the coil portion 40 is inserted between the lead portions 45A and 45B. It is intended. 47a is a sprocket hole of the lead frame.
[0037]
Such coil components are assembled in the order of steps shown in FIGS.
[0038]
As shown in FIG. 13, the terminal portions 42a and 42b in which the coil terminals 44a and 44b of the coil portion 40 are entangled are placed on the terminal receiving portions 46a and 46b of the pair of lead portions 45A and 45B. The coil portion 40 is inserted between the lead portions 45A and 45B by the above, and then, as shown in FIG. 14, the coil terminals 44a and 44b, terminals are connected by local heating using the laser light source as described in the above embodiment. At least a part of the parts 42a and 42b and the terminal receiving parts 46a and 46b are heated and melted to form connection parts 48a and 48b in which the above parts are electrically and mechanically connected.
[0039]
Next, as shown in FIG. 15, the connecting parts 48a and 48b and the coil part are molded with a molding material 49. At this time, the external connection portions of the lead portions 45A and 45B are exposed.
[0040]
Finally, as shown in FIG. 16, the lead portions 45A and 45B are separated from the lead frame 47, and the externally exposed ends of the separated lead portions 45A and 45B are bent upward so as to follow the upper end surface of the molding material 49. And finished product.
[0041]
The finished product is used by being mounted on the surface of, for example, a printed circuit board of an electronic component in an attitude in which the lead portions 45A and 45B are positioned at the bottom with the top and bottom reversed.
[0042]
(Fourth embodiment)
In FIG. 12, although the case where the coil terminals 44a and 44b are respectively entangled with the terminal portions 42a and 42b is shown, instead of this, as shown in FIG. 17, a cement wire is used for the coil terminals 44a and 44b, Or it is good also as arrangement | positioning along the terminal parts 42a and 42b, without using a jig | tool etc. If this form is adopted, the effect that the coil terminal does not get in the way when assembled to the lead frame and the assembly becomes extremely easy can be obtained.
[0043]
Even in the coil parts as described above, the effects as described in the above embodiments are exhibited.
[0044]
【The invention's effect】
According to the present invention described in detail above, the following effects can be obtained.
[0045]
According to the first aspect of the present invention, since at least a part of the coil terminal, the terminal part, and the terminal receiving part is melt-processed to electrically and mechanically connect the respective parts, compared with the conventional soldering process. Therefore, the tensile strength of the connection part is high, and the reliability can be improved. In addition, since melting is performed by partial (local) heating, the influence of heat on the coil portion is small and the reliability is further improved. Further, since the melting temperature is very high compared to the conventional soldering process, the thermal reliability of the connection portion is also increased even during the soldering process when mounting on a printed circuit board or the like in a subsequent process.
[0046]
In addition, since a cleaning process for flux, unnecessary solder, etc. is not required as in the prior art, the number of processes can be reduced and the cost can be reduced. Furthermore, since it is not necessary to use a solder material containing lead, the working environment can be improved.
[0047]
Further , since the terminal receiving portion provided on the lead is formed by the concave groove and the protruding piece protruding from the side wall, the terminal portion can be easily supported and positioned, and the protruding piece is melted so that the terminal portion and the coil terminal are melted. The connection strength is further increased because the binding portion is covered.
[0050]
Further, since the use of local heating means such as laser heating, it is possible to control the heating position, heating temperature, thereby further improving the workability.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a structure of a coil component according to a first embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view showing the manufacturing process of the coil component according to the first embodiment of the present invention.
FIG. 3 is a schematic cross-sectional view showing a manufacturing process of the coil component according to the first embodiment of the present invention.
FIG. 4 is a schematic cross-sectional view showing a manufacturing process of the coil component according to the first embodiment of the present invention.
FIG. 5 is a schematic sectional view showing the coil component according to the first embodiment of the present invention.
FIG. 6 is a flowchart showing the sequence of manufacturing steps of the coil component according to the first embodiment of the present invention.
FIG. 7 is an enlarged perspective view showing an example of a terminal receiving portion in the first embodiment of the present invention.
FIG. 8 is an enlarged perspective view showing another example of the terminal receiving portion in the first embodiment of the present invention.
FIG. 9 is an enlarged perspective view showing still another example of the terminal receiving portion in the first embodiment of the present invention.
FIG. 10 is an enlarged perspective view showing a magnetic core of a coil component according to a second embodiment of the present invention and a terminal portion of a modification.
FIG. 11 is an enlarged perspective view showing a magnetic core of a coil component according to a second embodiment of the present invention and a terminal portion receiving portion of another modification.
FIG. 12 is an exploded perspective view showing a coil component according to a third embodiment of the present invention.
FIG. 13 is a process side view of a coil component according to a third embodiment of the present invention.
FIG. 14 is a process side view of a coil component according to a third embodiment of the present invention.
FIG. 15 is a process side view of the coil component according to the third embodiment of the present invention.
FIG. 16 is a process side view of the coil component according to the third embodiment of the present invention.
FIG. 17 is a perspective view of main parts of a coil component according to a fourth embodiment of the present invention.
FIG. 18 is an exploded perspective view showing a manufacturing process of a conventional coil component.
FIG. 19 is a perspective view showing a conventional coil component.
FIG. 20 is a perspective view showing a conventional coil component.
FIG. 21 is an explanatory view showing the order of manufacturing steps of a conventional coil component.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Coil component 2a Terminal part 2b Terminal part 3 Magnetic core 3a Engagement receiving groove 4 Coil part 4a Coil terminal 4b Coil terminal 5a Lead part 5b Lead part 6a Terminal receiving part 6b Terminal receiving part 7a Concave groove 7b Concave groove 8a Protruding piece 8b Projection piece 10 Lead frame 11 Resin mold 12 Projection piece 13 Concavity and convexity portion 14 Insertion region 15 Insertion receiving piece 22a Terminal portion 23a Terminal portion 24a End surface member 24b End surface member 32a Terminal portion 32b Terminal portions 33a and 33b Terminal members 34a and 34b End surface member 35a , 35b, 35a ′, 35b ′ engaging claw pieces 42A, 42B terminal plate 42a, 42b terminal portion 44 coil 44a, 44b coil terminal 45A, 45B lead portion 47 lead frame

Claims (1)

A terminal portion is formed to protrude from both side flange end faces, a coil is wound, a coil end of the coil is drawn out, and a magnetic core entangled with the terminal portion, and the terminal portion entangled with the coil end And a lead part for external connection having a terminal receiving part provided with a concave groove that can be fitted and a protruding piece protruding outward of the concave groove, and the lead part is formed with a flange end surface of the magnetic core. It is arranged so that a gap is formed between the in the terminal portion coil ends has been tied, the drawer end portion of the coil terminal is located in the gap, the coil terminal tying portion the terminal receiving parts are fitted placed so that such a position along the projecting piece, placed on the protrusion in the terminal receiving portion of the terminal receiving portion is mounted the said coil terminal tying was the terminal portion The terminal portion is the terminal receiving portion by locally heating the portion Coil component, characterized in that it is melted connected as covered by the projecting piece.

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